1. Field of the Invention
This invention involves an interlocking living hinge between a cover and a integral housing. More particularly, this invention is employed in an electrical connector having an hinged locking and terminal position assurance member connected to a connector housing by an interlocking living hinge.
2. Description of the Prior Art
Living hinges are commonly used on plastic components, such as electrical connector housings, to join two components of a thermoplastic insulating housing. The most common application for electrical connectors is to use a living hinge to join a cover to a main housing. The living hinge connects the two main components, such as the cover and the base of a connector housing, so that the entire assembly is an integral component. The living hinge is flexible so that the cover can be rotated into position closing an opening in the housing or base. Typically the thickness of the living hinge is less than adjoining components, and when molded from a appropriate material, the hinge is sufficiently flexible so that it can be bent without being destroyed or severed. However, living hinges are susceptible to damage if repeatedly flexed, and living hinges used on electrical connectors are typically not intended to be flexed for many cycles. There is also the problem of deterioration of the plastic material with time which can make the living hinge more brittle, and therefore more subject to damage, with time. Although some plastics are more suitable for use in living hinges, some of these plastics possess other characteristics that make them less suitable for use in a rigid insulating housing that must protect terminals and contact interfaces in the operational environment of the electrical connector.
One common use of living hinges for electrical connectors is to use the living hinge to connect a cover enclosing a wire insertion section of an electrical housing. This approach is commonly used with insulation displacement connectors in which the cover is applied after the wires are inserted in wire receiving slots. In such applications additional latches are commonly employed to secure the cover to the housing and the living hinge serve little if any purpose after the cover has been attached to the housing.
Rotating covers has also been employed as locking members in electrical connectors. These covers contain latching features that engage a terminal after it has been inserted into a terminal cavity in the housing. The living hinge holds the cover in a retracted position while the terminal or terminals are inserted into the housing. The cover is then rotated about the living hinge to bring the locking or latching surface into engagement with the terminal to prevent extraction of the terminal. In these applications the cover can include latching features that limit the function of the living hinge to the original mating of the cover with the housing.
In some electrical connector applications, such as automotive applications, it is especially important to insure that all terminals are properly positioned in an electrical connector housing on a mass production basis. Therefore terminal position assurance or terminal position assistance members have been employed. These members insure that the connector cannot be properly assembled unless all terminals are properly positioned in the connector housing. Furthermore it is important that two connectors cannot be mated unless terminals are properly positioned in the connector housing. One approach to providing terminal position assurance is to employ a sliding member that backs up or locks a separate terminal latch into place after the terminal has been properly inserted. Typically this separate terminal latch is a plastic beam that is integral with the housing and protrudes into the housing cavities into which the terminals are inserted from the rear. The terminal latch deflects out of the way to permit insertion of the terminal. When the terminal is completely inserted, the terminal latch then returns to its normal position. If the terminal latch is in its normal position, the terminal position assurance member can slide in behind the terminal latch. If the terminal has not been completely inserted, and the terminal latch remains at least partially deflected, the terminal position assurance member cannot be fully inserted. If the terminal position assurance member is located on the mating portion of the electrical connector, the connector cannot be mated unless the terminal position assurance member is properly positioned.
If a pivoting cover is to be reliably used as a terminal position assurance member, it is important that the cover be properly secured in all directions. If a living hinge it used, the living hinge may not provide a sufficiently reliable means of securing the terminal position assurance member along the portion of the cover to which the hinge is attached. Since space is always a significant problem, any means of assuring that the cover is properly retained in the event of damage to the living hinge must be small and relatively unobtrusive.